Coaxial connectors are already known for interconnecting two printed circuit cards, such a connector comprising a cylindrical first connector element designed to be secured at one end to a first printed circuit card, and a second cylindrical connector element designed to come into contact via one end with a second printed circuit card, each connector element having a central contact and an outer contact separated by insulation, the central and outer contacts of the first and second connector elements having mutually-contacting cylindrical bearing surfaces, resilient means being interposed between the first and second connector elements and urging the central and outer contacts of the second connector element towards the second printed circuit card.
The first connector element is secured, in particular by soldering, to the first printed circuit card, and the second card is caused to press against the second connector element, which is thus moved relative to the first connector element, the contacts of the second connector element being pressed under the action of the resilient means against conductive zones provided on the first card.
A connector of that type in which the resilient means are elastomer O-rings is described in U.S. Pat. No. 6,699,054, and a connector of that type in which the resilient means are compression springs is described in U.S. Pat. No. 6,776,668.
Presently-known coaxial connectors are of a structure that means they present large variations in impedance along their length. In particular, in the connector described in U.S. Pat. No. 6,776,668, there is a high impedance zone at the central contact of the second connector element.
In addition, known connectors do not accommodate a large stroke in the relative movement between the connector elements, which means that the cards must be spaced apart with great accuracy.